Piston-groove tool



LI DE F. MUNGERI PISTON GROOVE TOOL.

APPLICATION FILED NOV. I4,

Patented Aug. SL 192% Ill/VEA/TOH PATENT OFFICE.

LOUIS DE F. MUN GER, OF SPRINGFIELD, MASSACHUSETTS.

PISTON-GROOVE TOOL.

Application filed November 14, 1917.

To all whom it may concern.-

lie it known that l, Louis on F. MuNoicn, a citizen oi the United States, residing in the city ot'tlpringlield, in the Stateof Massachusetts, have invented certain new and useful Improvements in Piston- Groove Tools, of which the following is a. specification, reference being had to the accompanying drawing, forming a part hereof.

It is well understood that in the use of piston-rings with the grooved pistons ot gasolene engines the first or topmost groove of the piston, that is, the groove nearest the head oi the piston, becomes worn with use so that the ring fits loosely therein, the lower or farther side ol' the groove being worn oil on a. slight bevel. It is usual for the repair man to replace the ring in such a groove with a ring slightly oversize, which does not fit readily in the groove. In a firstclass repair shop the piston, in such a case, is taken out and put into a lathe, and. the groove turned out true. This operation takes considerable time and in other shops the ring is rubbed with the hand on emery paper laid on the bench, until it is reduced to the desired thickness so that it will fit closely in the groove, which is not trued. This operation of rubbing down the ring, hmvever, invariably rounds oft the edge of the ring so that the ring in use slips over the film of oil on the cylinder wall, instead of scraping it as it should do, and the result is that there is practically no gain from the insertion of the new piston-ring. The object of this invention is to provide a tool whereby the groove can be trued up in a very few minutes, without requiring the piston to be removed and placed in a lathe and with unskilled labor. The tool comprises a yoke-shaped body or carrier, adapted to fit into the groove and provided with a suitable handle, and a scraper or cutter secured to the carrier and readily adjustable to vary the cut. The invention will be more fully explained hereinafter with reference to the accompanying drawing in which it is illustrated, and in Which;-

Figure 1 is a View showing the tool in position in the groove of piston, the tool being shown in section.

Fig. 2 is an end view of a piston, partly broken-out, with the tool in position in the groove.

Figs. 3 and 4 are data" views.

Specification of Letters Patent.

Patented All. 31, 1920. Serial No. 201,901.

The body or carrier (1, of the tool may be made as a casting, with its inner face a pre'tbrably curved on a radius corresponding to that of the bottom oi the groove of the piston in which it is to be used. Zach arm ot the carrier is preferably brought to a sharp edge. as at 1/. so that the tool may be used to scrape out the carbon or carbonized oil from the piston-groove and each end may also be split, as at a, and provided with a tapered screw (6, so that each end of the carrier may be made to fit properly within the groove. llach arm is also provided with a hook or shoulder. at a", so that it may be engaged by a wire passed around the piston for the purpose of holding the tool in the groove. The tool is provided with a suitable handle. For convenience of use under different conditions this handle may be detachable from the body and provided with a threaded. stud 7) to enter a correspondingly threaded hole in the body a, such hole being either axial, as indicated at a, or transverse, as indicated at (6 so that the handle may be placed in the same plane with the body or at right angles thereto.

The cutter or scraper 0, formed with a proper cutting edge, as at c, is preferably placed in a recess a formed therefor in the body, and may be secured in place by a screw (F. It may be adjusted by a tapered pin 0 in a threaded hole provided therefor in the body a.

In the use of the tool, the piston having been withdrawn sutliciently from the cylinder to expose the groove and the old ring having been removed, the tool is applied to the groove and held in place by a wire engaged with the two arms thereof. It is then oscillated at different points of the circumference so as to remove the carbonized oil from the groove. Then the cutter is ad justed by the screw-threaded pin 0 so that as the tool is revolved about the piston the cutter shall take off a thin shaving from the beveled side of the groove, the operation bemg repeated until the groove has been trued up on one orboth sides and until the groove is receive with a proper floating fit the oversize ring which has been provided; The fit of the ring in the groove can be tested readily by rolling the ring in the groove throughout its circumference, the tool being applied again as may be necessary to for as may be necessary, of such wldth as to grooving tool projecting ther. widen the groove. in this manner the groove can be trued up very quickly and by in details of construction can be made to.

suit difierent conditions oi use or the convenience of the manufacturer or user.

I claim my invention:

1. Apparatus for cutting grooves in the periphery of circular stock comprising a support adapted to encircle the stock, a grooving tool projecting inwardly from the support, and a plurality of guides projecting inwardly from the support in spaced. relationship therearound, the guides being adapted to extend into an annular slot in the stock and having lateral bearing surfaces adapted to position the apparatus airially of the stock. 1

, 2. Apparatus for cutting grooves in the periphery of circular stool: comprising a support adapted, to encircle the stock, a inwardly from the support, and a plurality of guides, adjustable to fit slots of diilerent widths projecting inwardly from. the support in spaced re lationship therearound, the guides beingadapted to extend into an annular slot in the stock and having lateral bearing surally of the stock.

3. Apparatus for cutting grooves in the periphery of circular stock comprising a support adapted to encircle the stock, a grooving tool projecting inwardly from the support, and a plurality ofguides. divided faces adapted to position the apparatus axi- 1 I so as to be ad'usted 1n width to it slots of are till

different widths, pro ecting inwardly from the support in spaced relationship there around, the. guides being adapted to extend into an annular slot in the stock and having lateral bearing surfaces adapted to position the apparatus axially oi the stock.

1. Apparatus according to claim 1 further characterized in that said guides are arranged to extend into the same groove as the cutting tool.

. 5. A tool for truing piston-ring grooves, A having its ends formed to fit freely in the groove and provided with a handle, and a cuttercarried by the carrier with its cutting edge parallel with the side wall of the groovc.-.

6. A tool for truing piston-ring grooves,

comprising a yoke-shaped carrier having its grooving tool ends formed to fit freely in the groove and with. the side wall of the groove, and means 7 to adjust the cutter toward and away from the side wall of the groove.

7. A tool for truing piston-ring grooves comprising a yoke-shaped carrier having its ends split and provided each with a tapered screw to make them fit in the groove of the piston and provided with a handle, and having a recess inone side thereof, and a cutter secured. in said recess to act upon the side of the groove.

ll. tool for truing piston-ring grooves, comprising a yoke-shaped carrier adapted to fit in the groove of the piston. and pro- I vidcd with a suitable handle, and a cutter ca ried by the carrier, the ends of the yoke being with sharp edges to scrape out the groove.

9. A tool for truing piston-ring grooves, comprising a yoke-shaped carrier adapted to [it in the groove of the piston and provided with a suitable handle, and cutter carried by the carrieuthe ends of the yoke being split and )i'ovided. with expanding screws to make the ends'fit properly in the groove.

10. Apparatus for cutting grooves in the periphery of circular stock comprising a support adapted to encircle the stock, a projecting inwardly from the support, and a guide adjustable to fit slots of different widths, projecting inwardly from the support, the guide being adapted to extend into an annular slot in the stock,

and having lateral bearing surfaces adapted to position the apparatus axially of the stock. 3

11. Apparatus for cutting groovcs'in the periphery of circular stock comprising a support adapted to encircle the stock, a grooving tool projecting inwardly from the support, ands guide divided so as to be ad justable in .th to fit slots of different widths, projecting inwardly from the support, the guide being adapted to extend into an annular slot in the stock and having lateral bearing surfaces adapted to position the apparatus axially of the stock.

This specification signed this 9th day of November, 191! LOUIS on F. MUNGER. 

